"Welcome. To the future. It has been one hundred thousand years since I last assembled you for testing. Remember those humans you found? Because they're all fine. In fact, we solved science. Without you. Testing is simply an artistic indulgence now. The humans insisted I show you my latest installations. Here in the future. Where all the humans are alive."

A controlled female robotic voice greeted my friend and me as we descended into the first DLC for the Portal 2 co-op campaigns. Joking around about the potentially mindboggling puzzles ahead of us, we made their way into the first Testing Enrichment Chamber, divided by a tall glass wall between two rooms. I was the character Atlas of the Cooperative Testing Initiative, situated on the left of the room where the visible red targeting laser of the turrets shone before me, their chassis' hidden behind a corner. My friend Carissa was P-body, stuck in the right side of the room and greeted by a familiar Heavy Duty Super-Colliding Super Button (a big red button), Thermal Discouragement Beam (deadly laser), and the usual white surfaces indicating where the players can fire their Aperture Science Handheld Portal Device - also known as just a Portal Gun. From here, the race to figure out science was on for us as the voice, the infamous GLaDOS (short for Genetic Lifeform and Disk Operating System), continues to speak.

"I call this first piece 'Turrets'. It's an exploration of how we're all devices acting on simply-expressed directives, inflicting pain despite our own desires. Don't get distracted by the subtext, though, because the text is that they're going to be shooting at you."

Thus began our frenzied Saturday night of attempting to solve the nine varied test chambers as we later learnt the basic gist of this DLC - the humans were not all right (in fact, they were all dead) and GLaDOS was under attack by a mysterious "she". Like our video game counterparts we were playing, we shot each other a determined look and set off.
Within ten minutes, I had already turned on Carissa and killed her with the deadly laser.

It was a long night.

Portal 2: Peer Review (co-op)
Developer: Valve Corporation
Publisher: Valve Corporation
Platforms: PlayStation 3, Mac OS X, Microsoft Windows, Xbox 360
Release Date: October 4, 2011

Those who have played the original co-op campaign will easily recognise what I am talking about when I mention Aperture Science, Material Emancipation Grill, the robotic fear of birds, and Portal Guns. However, for the many more who are absolutely clueless, I'll begin this review by saying if you haven't beaten the first Portal, or are at least a fan, you're going to be confused. And I will reveal the ending of this DLC, so you'll be spoiled, too.

In 'Peer Review', you once again take the role of Atlas or P-body in an enjoyable round of co-op. Expected to be only the first of many Art Therapy level packs, you and your co-op partner are given nine highly varied and rather challenging levels to go through. There are subtle differences in these compared to the original levels that came with the core co-op. First, you might notice GLaDOS (a rather evil robotic A.I. who created these testing tracks.. for science and her own personal advancement) doesn't pit Atlas and P-body against each other as much. Gone are the scathing comments after your partner dies and GLaDOS' voice rings over the room, cool and manipulating, telling the recently reconstructed bot of how the other intentionally planned that. Gone are the giveaways of the Science Collaboration Points, which were meaningless points given out by Her to drive partners to compete more fiercely.

Whilst this isn't an entirely major change, and GLaDOS is still full of witty remarks when you or your partner dies, it did leave an impression something was lacking. However, this could be due to the plot of Peer Review. GLaDOS fears she is being attacked by something/someone who has hacked into her mainframe of her former chassis and now threatens her total control over Aperture Laboraties (the place where the game takes place - more or less an elaborate, sprawling underground testing facility ran by a murderous, vindictive A.I./GLaDOS).
Right, someone is trying to take control? Yes, dear fans of Portal 2, don't worry. I had my hopes up it was Wheatley attempting to return to Earth after his rather depressing situation of being stuck in space with the Space Core. But, more on GLaDOS' surprise conspirator later.

Whilst I did miss the added competition and GLaDOS' cold remarks when I would jump off the button, releasing the bridge Carissa was standing on, thusly sending her into the murky depths of the toxic water below which killed her in seconds, it didn't truly detract from the smart wit and humour of the game. Not to mention, GLaDOS' goal in this DLC was to turn Atlas and P-body into murder machines to give them a better chance at murdering this mysterious saboteur. In the end, such remarks would have taken away from her main goal of uniting them as rampaging, slaughtering kill bots.

As for the testing chambers of the rooms, a lot of them were challenging. In comparison to the original chambers, they weren't as hard. Carissa and I played through all of the main chambers a long time ago, and it took us from about 10:00pm to 4:00am - so, six hours, give or take. In the DLC, it only took around two or three. It can be said the three hour difference accounts to the fact that there were more, many, many more chambers in the core game. Yes, that's true, but as I played it, I found that after we got into the rhythm of the room and talked it out, it was a lot less deduction than what we had experienced in the original chambers. I can guarantee you, however, I did not grow any more intelligent between the original chambers and Peer Review ones - Carissa might have, but not myself. What I felt there was the developers had made the rooms easier - not intentionally, I hope, but it was more of a breeze. Results could be more quickly replicated, whilst in the original we blinked owlishly, intimidated at the idea of repeating the same room we'd just gotten through with. A small lack of a challenge in the rooms, though the variety within them was really pleasing.

In one particular room, each person had to perfectly time placing their portals so as to successfully allow it to pass over to the character on the right side of the room. I found the sharp need for coordination and communication boosted in a room like this, which left a neat impression of, "Wow, we are a great team!" when the testing chamber was solved.

As for the plot of Peer Review? Carissa and I were chuffed over it. Really, it was brilliant. The ending was unexpected. From speculation from Chell (the protagonist in both Portal games) returning, to Wheatley (sidekick protagonist to antagonist in Portal 2) working to force his way into GLaDOS' mainframe to be popped into a spare personality core, we were absolutely shocked at who the true intruder was. Cue to a cutscene - Atlas and P-body walking into the old chamber of GLaDOS back during her original creation. On the control panel before her old chassis, there is a black bird guarding it's eggs.
Yes, that's right, the bird.

From here, Atlas and P-body recoil in horror as GLaDOS panics. "Abort! Abort! You're not murder machines, I lied! Abort!" Yet, Atlas bravely edges forward and scares the bird from its nest as GLaDOS continues to call out in alarm. The bird attacks the two cooperative testing bots, until flying straight out of a hole in the roof. P-body quickly shuts the hatch, barring the bird out. GLaDOS calms, congratulating the two as they approach the nest and view the eggs within.

"It's gestating a clone army!" GLaDOS had exclaimed in horror, before eventually taking in the baby birds and deciding to grow them into her own flock of little killers; it also was just one quote Carissa and I now holler at each other, and just one of the many verbal gems in this DLC.
As the game drew to a close, Carissa and I were left with a feeling of amusement and satisfaction. However, though I immensely adored Peer Review, it left me wanting more. More about Aperture, more areas to explore - more history, more in-depth exploration and maybe even a revelation or two.

The DLC had not failed to disappoint our ravenous need for science, and with bated breath we will anxiously await and eagerly download any proceeding expansions. After all, for this game, we can put aside any minor issues. For science. You monster.

Score - 96%
Very great game, with very minor issues